Methods and apparatus relating to the supply of power to power over ethernet devices

ABSTRACT

An access point, which is a Power over Ethernet (PoE) Powered Device (PD) measures input voltage and input current. The access point determines a power requirement of the access point based on the measured current, measured voltage, and information about power requirements of access point components or devices coupled to the access point a power requirement of the access point. The access point communicates the determined power request to a power sourcing equipment (PSE), e.g., a network switch. In some embodiments, the access point further communicates one of: measured input current and measured input voltage to the PSE. The PSE uses the information received from the access point, e.g., power request and power measurements to determine an amount of power to be granted to the access point. If the access point does not receive the requested power level the access point selects internal components and/or external devices to de-power.

PRIORITY

This application is a continuation of and claims priority to U.S. patentapplication Ser. No. 16/287,853, filed Feb. 27, 2019 and entitled“Methods and Apparatus Relating to the Supply of Power to Power OverEthernet Devices.” The contents of this prior application is consideredpart of this application, and are hereby incorporated by reference intheir entirety

FIELD

The present application relates to communications systems, and moreparticularly, method and apparatus related to the supply of power toPower over Ethernet access points.

BACKGROUND

Various standards relate to the supply of power over Ethernet lines. Inaccordance with such systems at least two lines in a cable are normallyused to supply power to a device. The device being powered is oftenreferred to as a Powered Device (PD) with the device supplying the powersometimes being referred to as a Power Sourcing Equipment (PSE).

The distance between a PD, such as an Access Point (AP), and a PSE,e.g., switch, may vary from one PD to another. This makes the deliveryof power to the PD, somewhat unpredictable given that the line loss isunknown. While voltage and/or power may be monitored at a PSE, theactual amount of power delivered to the PD is not reliably known to thePSE due to line loss and/or other operating conditions that may affectthe amount of power reaching the PD(s) or to which power is beingsupplied.

Not only is the unpredictable nature of power loss during transmission afactor in the amount of power that may have to be supplied to a pair ofpower lines connected to the PD, the amount of power required by a PDwill vary from time to time based on a variety of factors such astemperature or features in use on the PD.

In order to ensure that PDs attached to a PSE receive adequate power,the PDs often request more power than they actually need or areprovisioned based on the assumption that the PDs will require more powerthan they will actually need. By providing PDs power based on worst caseexpectations the number of PDs that can be supplied at a given time maybe less than could otherwise be supported and/or some PDs are deniedpower which they could use, e.g., they are lower priority PDs than PDswhich are being over provisioned with power based on the lack ofreliable power requirement information.

In view of the above discussion it should be appreciated that there is aneed for methods and apparatus for reliability determining power needsand/or communicating power needs to Power Sourcing Equipment (PSE)supplying power in an Ethernet system.

SUMMARY

In various embodiments, sensors are provided within PDs to measure powerneeds for determining information which can be communicated to a PSE andbe used in determining line loss and/or transmission loss so that suchlosses can be factored into making power supply decisions.

In some embodiments, PDs include a voltage sensor, e.g. a voltmeter,that is used to measure a voltage across a sense resister that isconnected to a PoE power input. Based on the measured voltage dropacross the sense resistor and the known value of the sense resistor, theinput current to the PD is determined. Voltage is also measured on thePD PoE power input, e.g., the input line voltage at the PD isdetermined. In embodiments, input power is determined in the PD usingthe measured current and measured voltage. In some embodiments, atemperature sensor is also included in the PDs allowing for temperaturemeasurements at the PDs. The PDs include detectors which may be includedin a processor, or external to a processor, for detecting peripheraldevices coupled to the PD.

In some but not necessarily all embodiments the measured input current,and measured input line voltage and/or temperature measured at the PD isprovided to a processor in the PD. The processor controls the reportingof these measurements to the PSE along with power requests. Theprocessor in the PD determines the amount of power to be required for agiven time period based on the detected peripheral devices coupled tothe PD, the detected input voltage, the detected input current, and whenmeasured, the detected temperature. In cases where the PD is a wirelessdevice such as an AP, the required amount of power may be and sometimesis determined based on a number of transmitters and/or receives to bepowered during a given time period. The number of transmitters and/orreceives to be powered during a given time period may be determinedbased on a traffic load, e.g., the amount of traffic to be transmittedto devices and/or received from devices.

After determining the amount of power to be requested, the PD sends arequest to the PSE for the requested amount of power, e.g., a number ofwatts. The measured input line voltage, current, and/or temperature atthe PD may be communicated with the PoE power request or separately fromthe PoE power request.

The PSE, e.g., a PoE switch, receives the PoE power request from one ormore PDs and, in some cases, the measured line voltage, current, and/ortemperature at the requesting device. The PSE takes into considerationthe received measurement information, e.g., voltage at the PD, currentat the PD, and/or temperature. In some embodiments the PSE estimates theamount of power loss to the device due to transmission loss and takesthis into consideration when determining the amount of power to besupplied to the requesting device. For example, the amount of powerexpected to be lost due to transmission may be added to the amount ofpower requested when determining the requesting PDs actual power needs.

Based on the amount of power available at the PSE, the requested amountof power and reported measurement information from one or more PDs, thePSE determines the amount of power to be provided to individual PDsrequesting power. In some cases, depending on the priority of the deviceand/or the number of devices requesting power, the PSE may or may notgrant a PD all the power it is requesting.

The amount of power granted to individual PDs is communicated from thePSE to the PDs to which power grants are made. The power grant may, andin some embodiments does, not take into consideration the amount ofpower the PD allocated to transmission loss. The amount of powerindicated as being granted to a PD that is subject to a largetransmission loss may be lower, e.g., one or several watts lower, thanthe actual amount of power allocated by the PSE. In this way. PDs canmake power requests based on their actual expected needs, potentiallyplus some safety factor, without having to worry if they will sufferfrom extensive transmission power loss due to whether they are connectedto the PSE by a short or long set of lines.

A PD which receives a power grant that is less than a requested amountmay, and in some embodiments does, select peripheral devices and/orcomponents in the PD to de-power or operate at reduced power so that itsoperation stays within the allocated amount of power. For example, a PD,which is an AP, may choose to de-power a camera attached to the AP orde-power one or more receivers or transmitters in the AP to avoid usingmore than the allocated amount of power.

The voltage, current, and/or temperature measuring steps may beperformed periodically, e.g., every 30 seconds, based on some sort ofschedule or as power requirements or measured values change. Byproviding a PSE such as a PoE switch with information about the voltage,current, and/or temperature at the PD to which power is being supplied,the PSE can make more accurate determinations of the amount of requiredpower to a requesting PD and/or increase the reliability of the systemby supplying the amount of power needed to overcome transmission lossesto devices which may be located at any of a variety of differentdistances away from the PSE.

A exemplary method, in accordance with some embodiments, comprises:measuring, in an access point, an input current for the access point;measuring, in the access point, a voltage on a Power Over Ethernet (PoE)power input of the access point; determining, in the access point, basedon the measured current, measured voltage, and information about powerrequirements of access point components or devices coupled to the accesspoint a power requirement of the access point, said power requirementbeing an amount of power to be requested; and communicating, from theaccess point, a power request to a Power Sourcing Equipment (PSE)indicating the determined power requirement.

An exemplary access point, in accordance with some embodiments,comprises: a plurality of wireless interfaces; a Power over Ethernet(PoE) power input; one of a: current sense resistor or an inductivecurrent sensor for measuring the input current to the access pointprovided via the POE power input; a voltage measurement device formeasuring at least one of: i) a voltage on a Power Over Ethernet (PoE)power input of the access point or ii) a voltage drop across said senseresistor; a processor configured to determine, in the access point,based on the measured current, measured voltage, and information aboutpower requirements of access point components or devices coupled to theaccess point a power requirement of the access point, said powerrequirement being an amount of power to be requested; and an interfacefor communicating, from the access point, a power request to a PowerSourcing Equipment (PSE), the power request indicating the determinedpower requirement.

While various features discussed in the summary are used in someembodiments it should be appreciated that not all features are requiredor necessary for all embodiments and the mention of features in thesummary should in no way be interpreted as implying that the feature isnecessary or critical for all embodiments.

Numerous additional features and embodiments are discussed in thedetailed description which follows.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a drawing of an exemplary communications system including aPower Sourcing Equipment (PSE), a plurality of wireless access points(APs), each AP coupled to the PSE via a Power over Ethernet (PoE) cable,and a plurality of user equipment (UE) devices, in accordance with anexemplary embodiment.

FIG. 2 is a drawing of a portion of an exemplary communications systemincluding a power sourcing equipment (PSE) coupled to a wireless accesspoint (AP) via a Power over Ethernet (PoE) cable, in accordance with anexemplary embodiment, said wireless access point implemented to measureaccess point input current using a sense resistor, determine an amountof power to be requested based on the measured current, and communicatea power request to the PSE.

FIG. 3 is a drawing of a portion of an exemplary communications systemincluding a power sourcing equipment (PSE), e.g., a network switch,coupled to a wireless access point (AP) via a Power over Ethernet (PoE)cable, in accordance with an exemplary embodiment, said wireless accesspoint implemented to measure access point input current using aninductive current sensor, determine an amount of power to be requestedbased on the measured current determine an amount of power to berequested based on the measured current, and communicate a power requestto the PSE.

FIG. 4A is a first part of an exemplary method of operating acommunications system including a wireless access point coupled to a PSEvia a PoE cable, in accordance with an exemplary embodiment, saidexemplary method including power control related operations.

FIG. 4B is a second part of an exemplary method of operating acommunications system including a wireless access point coupled to a PSEvia a PoE cable, in accordance with an exemplary embodiment, saidexemplary method including power control related operations.

FIG. 4 comprising the combination of FIG. 4A and FIG. 4B.

FIG. 5A is a drawing of a first part of an exemplary assembly ofcomponents which may be included in an exemplary wireless access pointin accordance with an exemplary embodiment.

FIG. 5B is a drawing of a second part of an exemplary assembly ofcomponents, which may be included in an exemplary wireless access pointin accordance with an exemplary embodiment.

FIG. 5 comprises the combination of FIG. 5A and FIG. 5B.

FIG. 6 is a drawing of exemplary data/information which may be includedin a wireless access point in accordance with an exemplary embodiment.

FIG. 7 is a drawing of an exemplary assembly of components, which may beincluded in an exemplary wireless access point in accordance with anexemplary embodiment.

FIG. 8 is a drawing of exemplary data/information which may be includedin an exemplary power sourcing equipment (PSE), e.g., a network switch,in accordance with an exemplary embodiment.

DETAILED DESCRIPTION

FIG. 1 is a drawing of an exemplary communications system 100 includinga Power Sourcing Equipment (PSE) 102, e.g., a network switch, aplurality of wireless access points (APs) (104, 106, 108, . . . 110),each AP coupled to the PSE 102 via a Power over Ethernet (PoE) cable,and a plurality of user equipment (UE) devices, in accordance with anexemplary embodiment. The plurality of wireless access points includewireless access point 1 104, wireless access point 2 106, wirelessaccess point 2 106, wireless access point 3 108, and wireless accesspoint n 110. In the exemplary system 100 of FIG. 1, each of the wirelessaccess points (104, 106, 108, . . . 110) is a WiFi/Bluetooth, e.g.,Bluetooth Low energy, access point, which is an Ethernet Powered Device(PD). In some embodiments, different APs coupled to the PSE 102 havedifferent capabilities, e.g., different types of radios, differentnumbers of radios, different external ports for powering additionalpowered devices and/or different power requirements.

Wireless access point 1 104 is coupled to PSE 102 via Power overEthernet (PoE) cable 105. Wireless access point 2 106 is coupled to PSE102 via Power over Ethernet (PoE) cable 107. Wireless access point 3 108is coupled to PSE 102 via Power over Ethernet (PoE) cable 109. Wirelessaccess point n 110 is coupled to PSE 102 via Power over Ethernet (PoE)cable 111. In some embodiments, at least some of the PoE cables (105,107, 109, 111) are different lengths.

System 100 includes a plurality of user equipment (UE) devices including(UE 1A 120, UE NA 122, UE 1B 124, UE NB 126, UE 1C 128, UE NC 1 130, UE1D 132, UE ND 134). At least some of the UEs (120, 122, 124, 126, 128,130, 132, 134) are wireless device which may move around thecommunications system and be connected to different wireless accesspoints at different times. In the example of FIG. 1, UE 1A 120 and UE NA122 are shown as being coupled to wireless access point 1 104 viawireless links 121, 123, respectively. In the example of FIG. 1, UE 1B124 and UE NB 126 are shown as being coupled to wireless access point 2106 via wireless links 125, 127, respectively. In the example of FIG. 1,UE 1C 128 and UE NC 130 are shown as being coupled to wireless accesspoint 3 108 via wireless links 129, 131, respectively. In the example ofFIG. 1, UE 1D 132 and UE ND 134 are shown as being coupled to wirelessaccess point 4 110 via wireless links 133, 135, respectively.

There may be, and sometimes are one or more external devices connectedto an access point which can be, and sometimes are powered, e.g.,conditionally powered, by the access point. One or more of externaldevices (device 1 a 140, . . . , device Na 142) may be, and sometimesare, connected to AP 1 104, and powered, e.g., conditionally powered, byAP 1 104. One or more of external devices (device 1 b 144, . . . ,device Nb 146) may be, and sometimes are, connected to AP 2 106, andpowered, e.g., conditionally powered, by AP 2 106. One or more ofexternal devices (device 1 c 148, . . . , device Nc 150) may be, andsometimes are, connected to AP 3 108, and powered, e.g., conditionallypowered, by AP 2 106. One or more of external devices (device 1 d 152, .. . , device Nd 154) may be, and sometimes are, connected to AP n 110,and powered, e.g., conditionally powered, by AP n 110.

In the exemplary system 100 of FIG. 1, at least one of the wirelessaccess points (104, 106, 108, 110) includes the capability to measureinput current, measure input voltage. determine, based on the measuredcurrent, measured voltage and information about power requirements ofaccess point components or devices coupled to the access point, a powerrequirement of the access point, and communicate a power request to aPower Sourcing Equipment (PSE) indicating the determined powerrequirement. In some such embodiments, the access point furthercommunicates: i) measured input voltage and measured input current, orii) measured input power, to the PSE, which allocates power grants tothe access point based on information received from the access point.

FIG. 2 is a drawing of a portion 200 of an exemplary communicationssystem including a power sourcing equipment (PSE) 201, e.g., a networkswitch, coupled to a wireless access point (AP) 202, e.g. aWiFi/Bluetooth AP, which is a powered device (PD), via a Power overEthernet (PoE) cable 203. In one exemplary embodiment PSE 201 of FIG. 1is PSE 102 of FIG. 1, wireless access point 202 of FIG. 2 is one of thewireless APs (102, 104, 106, 110) of FIG. 1, and PoE cable 203 of FIG. 2is a corresponding one of the PoE cables (105, 107, 109, 111) of FIG. 1,respectively.

PSE 201 includes a PoE plus (PoE+) interface 204, a transmitter 205, aDC power supply 206, a receiver 207, a processor 208, an assembly ofhardware components 2081, e.g., an assembly of circuits, and memory 209.The transmitter 205, DC power supply 206, receiver 207, processor 208,assembly of components 2081 and memory 209, are coupled together via abus 210, over which the various components may exchange data andinformation. PoE+ interface 204 includes TX+ connection point 211, a TX−connection point 212, a first B+ connection point 213, a second B+connection point 214, a first B− connection point 215, a second B−connection point 216, a RX+ connection point 217 and a RX− connectionpoint 218. The TX+/TX− connection point pair (211, 212) is coupled tothe transmitter 205. The two B+ connection points (213, 214) are coupledtogether and connected to a high side output of DC power supply 206. Thetwo B− connection points (214, 215) are coupled together and connectedto a low side output of DC power supply 206, which is connected to PSEground 290.

Wireless AP 202 includes PoE+ interface 219, receiver 220, wirelessinterfaces (I/Fs) 221, transmitter 222, processor 223, e.g., a CPU, anassembly of components (AOC) 2231, e.g. an assembly of hardwarecomponents, e.g., circuits, and memory 224. Memory 224 includes acurrent determination component 224, e.g. a current determinationroutine, and a power determination component 245, e.g., a powerdetermination routine. The receiver 220, wireless interfaces (I/Fs) 221,transmitter 222, processor 223, and memory 224 are coupled together viaa bus 2210 over which the various elements may interchange data andinformation. Wireless AP 202 further includes a sense resistor 235, afilter circuit 226, Dc/DC convertor 227, monitoring device 228, and areference voltage generation circuit 225, coupled together as shown inFIG. 2. Filtering circuit 226 includes a common mode choke 246, andcapacitors 247, 248, 249.

Monitoring device 228, e.g., an integrated circuit chip, includes avoltage measurement device 250, a temperature sensing device 251, ananalog to digital converter 252, a processor 253, memory 254 and adigital I/O interface 255, e.g., a I2C interface, coupled together asshown in FIG. 2. The digital I/O interface includes a clock input 256,and a Data input/output (I/O) 257. In some embodiments, monitoringdevice 228 is, e.g., an integrated circuit chip such as, e.g., ahigh-side current-sense amplifier with an Analog-to-Digital Converter(ADC) and Operational amplifier (Op Amp) and gain block.

Wireless I/Fs 221 includes four wireless radios (WiFi radio 1 259, WiFiradio 2 260, WiFi radio 3 261, Bluetooth Low Energy (BLE) radio 262). Insome embodiments, each wireless radio (259, 260, 261, 262) is considereda wireless interface. WiFi radio 1 259, e.g., a 2.4 GHz radio, includesa wireless receiver 2591, a wireless transmitter 2592 and power controlcircuitry 255. WiFi radio 2 260, e.g., a 5 GHz radio, includes awireless receiver 2601, a wireless transmitter 2602 and power controlcircuitry 266. WiFi radio 3 261, e.g., a dual band radio, includes awireless receiver 2611, a wireless transmitter 2612 and power controlcircuitry 267. BLE radio 262 includes a wireless receiver 2621, awireless transmitter 2622 and power control circuitry 268. At differenttimes different sets of wireless radios or different sets oftransmitters of the wireless radios may be powered on (energized) orpowered off (de-energized). Each of the radios (259, 260, 261, 262) ofthe wireless interface 221 may be, and sometimes is, coupled to one ormore of a plurality of antenna (antenna 1 263, . . . , antenna M 264),via which the receivers (2591, 2601, 2611, 2621), respectively, mayreceive wireless signals, e.g., from UE devices. Each of the radios(259, 260, 261, 262) of the wireless interfaces 221, may be, andsometimes is, coupled to one or more of the plurality of antenna(antenna 1 263, . . . , antenna M 264), via which the transmitters(2592, 2602, 2612, 2622), respectively may transmit wireless signals,e.g., to UE devices. Different WiFi radios may, and sometimes do, usedifferent antennas. In some embodiments, different antennas are used fortransmit and receive. In some embodiments, at least some of the WiFiradios (259, 260, 261, 262) support MIMO operations. In someembodiments, wireless radios, wireless radio transmitters, and/or MIMOcircuitry can be, and sometimes are, selectively de-energized to reducepower, e.g., via power control circuitry (265, 266, 267, 268), e.g.,under the direction of processor 223.

PoE+ interface 219 includes RX+ connection point 236, a RX− connectionpoint 237, a first B+ connection point 238, a second B+ connection point239, a first B− connection point 240, a second B− connection point 241,a TX+ connection point 242 and a TX− connection point 243. The RX+/RX−connection point pair (236, 237) is coupled to the receiver 220. The twoB+ connection points (238, 239) are coupled together and connected to aninput side of current sense resistor 235. The output side of the currentsense resistor 235 is connected to an input high side of the common modechoke 246 of the filter circuit. The two B− connection points (240, 241)are coupled together and connected to a Power Device (PD) ground (GND)291 and to an input low side of the common mode choke 246 of the filtercircuit. The Hi side output of the common mode choke is connected to theHi side input of the DC/DC converter 227. The low side output of thecommon mode choke 246 is connected to forward ground 292 and to the lowside input of the Dc/DC convertor. The DC/DC converter 227 generates aplurality of DC voltages (V1, V2, . . . VN) 297 which are output topower the wireless access points internal components and devices,external to the wireless access point, which are being powered by thewireless access point, e.g., USB powered devices, Internet of Things(IoT) devices, and/or an additional PoE Powered Device, e.g., anotherwireless base station or another type of PoE PD.

Wireless access point 202 further includes Internet of Things (IoT)ports 229 coupled to IoT port circuitry 230. IoT port circuitry 230includes detection circuitry 230, sometimes referred to as sense (S)circuitry, for detecting: one of more of the following: i) if one ormore IoT devices are connected to the IoT ports, ii) the number of IoTconnected devices, iii) information used to identify and/or characterizethe type of device detected, e.g., in terms of power draw, or iv) ameasured level of power draw. IoT port circuitry 230 further includespower control circuitry 275, e.g., activating or de-activating a IoTdevice, e.g., de-powering a connected IoT device, under control ofprocessor 223 to reduce power draw. One or more IoT devices (device 1B269, . . . , device NB 270) may, be and sometimes are coupled to theaccess point 202 via IoT ports 229.

Wireless access point 202 further includes a module ports 231 coupled tomodule port circuitry 232. Module port circuitry 232 includes detectioncircuitry 276, sometimes referred to as sense (S) circuitry, fordetecting: one of more of the following: i) if a powered device, e.g., aPoE Powered Device is connected to the module port ii) information usedto identify and/or characterize the type of device detected, e.g., interms of power draw, or iii) a measured level of power draw. Module portcircuitry 232 further includes power control circuitry 279, e.g., foractivating or de-activating a PD, e.g., de-powering a connected PD,under control of processor 223 to reduce power draw. A PD 271, e.g.,another PoE access point or another type of PD may, be and sometimes iscoupled to the access point 202 via module ports 231.

Wireless access point 202 further includes USB ports 233 coupled to USBports circuitry 234. USB ports circuitry 234 includes detectioncircuitry 278, sometimes referred to as sense (S) circuitry, fordetecting: one of more of the following: i) if one or more USB devicesare connected to the IoT ports, ii) the number of USB connected devices,iii) information used to identify and/or characterize the type ofdevice(s) detected, e.g., in terms of power draw, or iv) a measuredlevel(s) of power draw. USB ports circuitry 234 further includes powercontrol circuitry 279, e.g., for activating or de-activating a USBdevice, e.g., de-powering a connected USB device, under control ofprocessor 223 to reduce power draw. One or more USB devices (externaldevice 1A 272, . . . , external device NA 273) may, be and sometimes arecoupled to the access point 202 via USB ports 233.

PoE+ cable 203 includes line 280 which connects TX+ 211 of PSE 201 toRX+ 236 of access point 202. PoE+ cable 203 further includes line 281which connects TX− 212 of PSE 201 to RX− 237 of access point 202. Powerallocation message signals 288, which generated and sent by transmitter205 of PSE 201, are communicated via cable line pair (280, 2281) ofcable 203, to wireless access point 202, and the signals are received byreceiver 230 of the access point 202. The receiver 220 communicates thereceived power allocation message 288 to processor 223.

PoE+ cable 203 further includes line 282 which connects B+ 213 of PSE201 to B+ 238 of access point 202. PoE+ cable 203 further includes line283 which connects B+ 214 of PSE 201 to B+ 239 of access point 202. PoE+cable 203 further includes line 284 which connects B− 215 of PSE 201 toB− 240 of access point 202. PoE+ cable 203 further includes line 285which connects B− 216 of PSE 201 to B− 241 of access point 202. Power issupplied from PS 201 to wireless access point via lines (282, 283, 284,285), e.g., with 2 lines (282, 283) being the high side and two lines(285, 285) being the Low or return side. In some embodiments, only 2lines are used to supply power (one B+ line and one B− line), ratherthan 4 lines. The embodiment with 4 power lines can support higher powerlevels than the embodiment with only 2 power lines.

The input voltage (VIN) 299 of the wireless access point 202 is shownacross the common connection point of B+ 238 and B+ 239 with respect tothe common connection point of B− 240 and B− 241. The input voltage(VIN) 299 of the access point 202 is measured by the access point. Theinput current TIN 298, which is the current through current senseresistor 235, is also measured by the access point 202. In thisexemplary embodiment, the voltage measurement device 250 of measurementdevice, receives as inputs V+ and V−, which are sense points one bothsides of sense resistor 250. Voltage measurement device 250 measures thevoltage drop across sense resistor 235, e.g. (the value of V+ withrespect to PD In GND)−(the value of V− with respect to PD In GND). Themeasured voltage drop across the sense resistor is output from voltagemeasurement device, e.g., a voltage measurement circuit, and input toADC 252, where the analog measurement is converted to a digital value.The digital value representing the voltage drop across the senseresistor is input to processor 253. In some embodiments, the monitoringdevice 228 knows the value of the sensor resistor 235, and computes aninput current, e.g., where input current=measured voltage drop acrosssense resistor/value of the sense resistor. In other embodiments, themonitoring device 228 is not aware of the value of the sense resistorand outputs the measured voltage drop across the sense resistor or ascaled value corresponding to the measured voltage drop across the senseresistor to process or 233, which determines the input current. Forexample, the CPU 223 retrieves the value of the sense resistor, which isstored in memory, and CPU 223 calculates the value of the input current,where input current=voltage drop across the sense resistor/senseresistor value.

In some embodiments, the voltage measurement device 250 measures theinput voltage Vin 299, which is V+ with respect to PD IN GND, directly,outputs, the analog measurement to the ADC 252, which converts it to adigital representation, forwards the result to the processor 253, whichsends the measured voltage in a message to CPU 223.

In some embodiments, the voltage measurement device 250 measures anaverage voltage of V+ and V−, sometimes referred to as an input commonmode voltage for device 228, sends the measured average voltage to ADC252, where the ADC converts the analog measurement to a digitalrepresentation. Then the result is forwarded to the processor 253, whichsends the average voltage (common mode input voltage) to CPU 223 in amessage. In some embodiments, processor 223 uses the average voltage(common mode input voltage) as a reasonable representation of VIN, sincethe voltage drop across the sense resistor is relatively small. In otherembodiments, the CPU 223 adjusts the received average voltage (commonmode input voltage) taking into account the voltage drop across thesense resistor, based on the measured current through the sense resistorand the known value of the sense resistor.

Temperature sensing device 251, e.g., a temperature sensing circuitincluding a calibrated temperature sensitive component, e.g., resistorwith a known resistance vs temperature curve, or a thermocouple,measures the temperature of access point 202 and outputs and analogsignal indicative of the measured temperature to ADC 252, which convertsthe analog signal to a digital representation of the temperature, andsends the digital representation to processor 253. In some embodiments,access point power use increases as temperature increases, e.g., becauseone or more cooling fans are turned-on and/or operate at a higher on/offduty cycle ratio.

Clock input 256 of Digital I/O interface 255 receives clock signals 293from processor 233. Serial data line 294 couples Data I/O 257 ofmonitoring device 228 to processor 223. Exemplary signals 295 sent fromprocessor 228 to Data I/O 257 over serial I/O 294 include configurationand control messages, e.g., messages selecting types of measurements tobe performed, rates of measurements to be performed, scale factors to beused, which messages are to be output, rate of messages to be output,and format of output messages. Exemplary signals 296 sent from data I/O257 to processor 223 include, e.g., a messages communicating a measuredor determined current, a message communicating measured voltage, amessage communicating a voltage drop across the sense resistor, amessage communicating a common mode input voltage, and a messagecommunicating a measured temperature at the access point.

FIG. 2 has been described for an embodiment in which 4 lines are usedfor power (two B+ lines and two B− lines). In some embodiments, only twolines are used for power (one B+ line and one B− line). FIG. 2 has beendescribed for an exemplary implementation using PoE+; however, themethods and apparatus described in this application are also well suitedfor other Power over Ethernet implementations, e.g., an earlier PoEimplementation using lower maximum power levels than PoE+, or a newerPoE implementation using higher maximum power levels than PoE+.

FIG. 3 is a drawing of a portion 300 of an exemplary communicationssystem including a power sourcing equipment (PSE) 201, e.g., a networkswitch, coupled to a wireless access point (AP) 202′, e.g. aWiFi/Bluetooth AP, which is a powered device (PD), via a Power overEthernet (PoE) cable 203. In one exemplary embodiment PSE 201 of FIG. 3is PSE 102 of FIG. 1, wireless access point 202′ of FIG. 3 is one of thewireless APs (102, 104, 106, 110) of FIG. 1, and PoE cable 203 of FIG. 3is a corresponding one of the PoE cables (105, 107, 109, 111) of FIG. 1,respectively.

FIG. 3 is similar to FIG. 2; however, wireless access point 202′ of FIG.3 is slightly different from wireless access point 202 of FIG. 2. Thedifference between access point 202 of FIG. 2 and access point 202′ ofFIG. 3 will now be described. Access point 202 of FIG. 2 includes asense resistor 235 and monitoring device 228 performs a voltage dropmeasurement across sense resistor 235, which is used to measure inputcurrent IIN 298. Access point 202′ of FIG. 3 does not include senseresistor 235, but rather includes an inductive current sensor 235′, e.g.an inductive pick-up, around an input power feed line as shown in FIG.3, and monitoring device 228′ includes a current measurement device2501, which is coupled to inductive current sensor 235′, whichdetermines a current value based on the received signal from theinductive current sensor 235′. The current measurement device 2501outputs an analog signal indicative of the input current to ADC 252,which converts the analog measurement to a digital value, which is sentto processor 253. Voltage measurement device 250′ of monitoring device228′ measures Vin 299 and outputs an analog signal indicative of themeasured voltage to the ADC 252, which converts the analog measurementto a digital value, which is sent to processor 253.

FIG. 4, comprising the combination of FIG. 4A and FIG. 4B, is aflowchart 400 of an exemplary method, e.g., a method of operating acommunications system including a Power Sourcing Equipment (PSE) and anaccess point which is a Powered Device (PD), in accordance with anexemplary embodiment. Operation starts in step 402 in which thecommunications system is powered on and initialized. Operation proceedsfrom step 402 to step 404.

In step 404 an access point measures, at the access point, an inputcurrent for the access point. In some embodiments, step 404 includesstep 406; while in other embodiments, step 404 includes step 408.

In step 406 the access point measures, in the access point, a currentthrough a sense resistor, said sense resistor being in series with apower over Ethernet (PoE) power input of the access point. In someembodiments, step 406 includes steps 410 and 412. In step 410 the accesspoint measures a voltage drop across said sense resistor. Operationproceeds from step 410 to step 412. In step 412 the access pointdetermines the current based on the voltage drop across the senseresistor and the known value of the sense resistor. For example, current(in amps)=measured drop across the sensor resistor (in volts)/value ofsense resistor (in ohms).

In step 408 the access point measures, in the access point, a currentthrough an input power feed line coupled to a power over Ethernet (PoE)power input of the access point, said current measurement beingperformed using an inductive sensor.

Operation proceeds from step 404 to step 414. In step 414 the accesspoint measures, in the access point, a voltage on a power over Ethernet(PoE) power input of the access point. For example, the access pointmeasures the on the B+ power input line with respect to ground (e.g.,the B− power input line).

Steps 416, 418, and 420 are optional steps. In some embodiments, one ormore or all of steps 416, 418, and 420, are performed. In someembodiments, one or more or all of optional steps 416, 418, and 420 arenot performed, and the step is bypassed in the sequence of steps. Theflow will now be described for an embodiment, in which each of steps416, 418 and 420 are performed. Operation proceeds from step 414 to step416. In step 416, the access point measures, a temperature at the accesspoint. Operation proceeds from step 416 to step 418, In step 418 theaccess point, determines a number of wireless transmitters to be poweredon based on a traffic load to be communicated. In some embodiments, thedetermination of the number of wireless transmitter to be powered on isfurther based on the device capabilities of user devices to be servicedby the access point. Operation proceeds from step 418 to step 420. Instep 420 the access point detects peripheral devices attached to theaccess point. Operation proceeds from step 420 to step 422.

In step 422 the access determines, based on the measured current,measured voltage, and information about power requirements of accesspoint components or devices, e.g., peripheral devices, coupled to theaccess point a power requirement of the access point, said powerrequirement being an amount of power to be requested. In someembodiments, the devices coupled to the access point include one or moreof: another PD, e.g., an additional PoE AP or another type of PoEcoupled to the access point via a module port, one or more USB powereddevices coupled to the access point via a USB port, or one or moreInternet of Things (IoT) devices coupled to the access point via a IoTport.

In some embodiments, step 422 includes one or more or all of steps 424,426 and 428. In step 424 the access point determines the powerrequirement of the access point based on the measured temperature inaddition to the measured current, measured voltage and the powerrequirements of access point components or devices coupled to the accesspoint. In step 426 the access point determines the amount of power to berequested based on the determined number of wireless transmitters to bepowered on. In step 428 the access point determines the amount of powerto be requested based on the peripheral devices which are detected asbeing attached to the access point.

Operation proceeds from step 422, via connecting node A 430, to step432. In step 432 the access point communicates, from the access point,at least one of: the measured current and measured voltage or ii)measured power to the power sourcing equipment (PSE), wherein themeasured power equals the measured voltage multiplied by the measuredcurrent. Operation proceeds from step 432 to step 434. In step 434 theaccess point communicates from the access point, a power request to thepower sourcing equipment (PSE) indicating the determined powerrequirement. Operation proceeds from step 434 to step 436.

In step 436 the PSE determine at least one of: a current, a voltage orpower to apply to the power lines used to supply power to the accesspoint based on the requested amount of power and at least one of: i) thecommunicated measured current and measured voltage or ii) thecommunicated measured power. For example, the PSE can take inconsideration voltage drop/power loss on the line to determine the powerto be applied at the PSE, e.g., the access point may not be aware of theamount of line loss, but once i) AP measured current and AP measuredvoltage or ii) AP measured power is reported to the PSE, the PSE canfactor into its power calculations the power loss since the PSE measuresvoltage at its location on the lines being used to supply power to theAP. Operation proceeds from step 436 to step 438.

In step 438, the access point receives a response to said power request,said response being sent from said PSE. Operation proceeds from step 438to step 440.

In step 440 the access point determines if the received responseindicates a power grant that is less than the determined amount of powerthat was previously requested by the access point. If the access pointdetermines the received response indicates a power grant that is lessthan the determined amount of power that was requested by the accesspoint, then operation proceeds from step 440, to step 442; otherwise,operation proceeds from step 440, via connecting node B 446 to step 404.

In step 442 the access point selects one or more access point componentsor devices coupled to the access point to de-power, when said responsefrom the PSE indicated a power grant less that the amount of power thatwas requested. Operation proceeds from step 442 to step 444. In step 444the access point de-powers the selected one or more access pointcomponents or devices coupled to said access point. Operation proceedsfrom step 444, via connecting node B 446, to step 402. The access pointproceeds through the steps of the flowchart again, repeating thepreviously described steps, e.g., including the steps of: measuringinput current for the access point (repeat step 402), measuring voltageon a PoE power input of the access point (repeat step 404), determiningbased on the measured current, measured voltage, and information aboutpower requirements of access point components or devices coupled to theaccess point, an amount of power to be requested (repeat step 422),communicating at least one of: the measured current and measured voltageor ii) measured power to the power sourcing equipment (PSE) (repeat step432), and communicating the power request to the PSE (repeat step 434),etc.

In various embodiments, the access point is a powered device (PD). Insome such embodiments, the access point is powered by the PSE. In somesuch embodiments, the PSE supports PoE plus (PoE+) and the access pointis a PoE+ device.

FIG. 5, comprising the combination of FIG. 5A and FIG. 5B, is a drawingof an exemplary assembly of components 500, comprising part A 501 andPart B 503, which may be, and sometimes is, included in an exemplarywireless access point in accordance with an exemplary embodiment.Exemplary assembly of components 500, which may be included in awireless access point which is a power device (PD) such any of theexemplary wireless access points (104, 106, 108, 110 of FIG. 1, wirelessaccess point 202 of FIG. 2, and/or wireless access point 202′ of FIG. 3,implement steps of an exemplary method, e.g., steps of the method of theflowchart 400 of FIG. 4, which are performed by a wireless access point.

Assembly of components 500 can be, and in some embodiments is, used in awireless access point of FIG. 1, e.g. wireless access point 1 104 ofFIG. 1, wireless access point 202 of FIG. 2 and/or wireless access point202′ of FIG. 3. The components in the assembly of components 500 can,and in some embodiments are, implemented fully in hardware within theprocessor 223, e.g., as individual circuits. The components in theassembly of components 500 can, and in some embodiments are, implementedfully in hardware within the assembly of components (AOC) 2231, e.g., asindividual circuits corresponding to the different components. In otherembodiments some of the components are implemented, e.g., as circuits,within the processor 223 with other components being implemented, e.g.,as circuits within assembly of components 2231, external to and coupledto the processor 223. As should be appreciated the level of integrationof components on the processor and/or with some components beingexternal to the processor may be one of design choice. Alternatively,rather than being implemented as circuits, all or some of the componentsmay be implemented in software and stored in the memory 224 of thewireless access point, with the components controlling operation of thewireless access point to implement the functions corresponding to thecomponents when the components are executed by a processor, e.g.,processor 223. In some such embodiments, the assembly of components 500is included in the memory 224. In still other embodiments, variouscomponents in assembly of components 500 are implemented as acombination of hardware and software, e.g., with another circuitexternal to the processor 223 providing input to the processor 223 whichthen under software control operates to perform a portion of acomponent's function. While processor 223 is shown in the FIGS. 2 and 3embodiments as a single processor, e.g., computer, it should beappreciated that the processor 223 may be implemented as one or moreprocessors, e.g., computers.

When implemented in software the components include code, which whenexecuted by the processor 223, configure the processor 223 to implementthe function corresponding to the component. In embodiments where theassembly of components 500 is stored in the memory 224, the memory 224is a computer program product comprising a computer readable mediumcomprising code, e.g., individual code for each component, for causingat least one computer, e.g., processor 223, to implement the functionsto which the components correspond.

Completely hardware based or completely software based components may beused. However, it should be appreciated that any combination of softwareand hardware, e.g., circuit implemented components may be used toimplement the functions. As should be appreciated, the componentsillustrated in FIG. 5 control and/or configure the wireless accesspoint, e.g., wireless access point 202 or 202′ or elements therein suchas the processor 223, to perform the functions of corresponding stepsillustrated and/or described in the method of one or more of theflowcharts, signaling diagrams and/or described with respect to any ofthe Figures. Thus the assembly of components 500 includes variouscomponents that perform functions of corresponding one or more describedand/or illustrated steps of an exemplary method, e.g., steps of themethod of flowchart 400 of FIG. 4 and/or described or shown with respectto any of the other figures. In some embodiments, some of the componentsincluded in assembly of components 500 are included in processor 253,memory 254, or in hardware components shown in FIG. 2 or FIG. 3.

Assembly of components 500 includes a component 504 configured tooperate the access point to measure, in the access point, an inputcurrent for the access point. In some embodiments, e.g., the embodimentof FIG. 2 including wireless access point 202 which includes currentsense resistor 235, component 504 includes a component 506 configured tooperate the access point to measure, in the access point, a currentthrough a sense resistor, said sense resistor being in series with aPower over Ethernet (PoE) power input of the access point. Component 506includes a component 510 configured to operate a voltage measurementdevice, e.g., voltage measurement device 250, e.g., a voltagemeasurement circuit, to measure a voltage drop across said senseresistor, and a component 512 configured to determine the current basedon the measured voltage drop across the sense resistor and the knownvalue (known resistance) of the sense resistor. In some embodiments,e.g., the embodiment of FIG. 3 including wireless access point 202′which includes inductive current sensor 235, component 504 includes acomponent 508 configured to control a current measurement device, e.g.,current measurement device 2501, which uses inductive current sensor235, to measure, in the access point, a current through an input powerfeed line coupled to a Power over Ethernet (PoE) power input of theaccess point.

Assembly of components 500 further includes a component 514 configuredto control a voltage measure device, e.g., voltage measurement device250 or 250′, which may be a voltage measurement circuit, to measure, inthe access point, a voltage on a PoE power input of the access point,e.g., with respect to PD IN ground, and a component 518 configured tocontrol a device, e.g., a temperature sensing device 251, to measure inthe access point a temperature at the access point.

Assembly of components 500 further includes a component 518 configuredto determine a number wireless transmitters to be powered on based on atraffic load to be communicated, a component 520 configured to detect,at the access point, peripheral device(s) attached to the access point,e.g., based on input received from device detection circuits, sometimesreferred to as external device sense circuits, 274, 276, 278.

Assembly of components 500 further includes a component 522 configuredto determine in the access point, based on the measured current,measured voltage, and information about power requirements of accesspoint components (e.g., including TX 2592, TX 2601, TX 2612, TX 2622) ordevices (e.g., one or more of devices 259, 270, 271, 272, 283) coupledto the access point, a power requirement of the access point, said powerrequirement being an amount of power to be requested. Component 522includes a component 524 configured to determine the power requirementof the access point based on the measured temperature in addition to themeasured current, measured voltage and the power requirements of theaccess point or device coupled to the access point, a component 526configured to determine the amount of power to be requested based on thenumber of wireless transmitters to be powered on 526, and a component528 configured to determine the amount of power to be requested based onthe peripheral devices which are detected as being attached to theaccess point.

Assembly of components 500 further includes a component 531 configuredto generate a message communicating at least one of: i) the measuredcurrent and measured voltage or ii) a measured power to the PSE, whereinthe measured power equals the measured voltage multiplied by themeasured current, a component 532 configured to operate the access pointto send, e.g., via a transmitter 222, to said PSE said generated messagecommunicating at least one of: i) the measured current and the measuredvoltage or ii) a measured power to the PSE, wherein said measured powerequals the measured voltage multiplied by the measured current, acomponent 533 configured to generate a message communicating a powerrequest to the power sourcing equipment (PSE) indicating the determinedpower requirement, and a component 534 configured to operate the accesspoint to send, e.g., via a transmitter 222, to said PSE said generatedmessage communicating from the access point, a power request, to thepower sourcing equipment (PSE) indicating the determined powerrequirement.

Assembly of components 500 further includes a component 538 configuredto operate the access point to receive, e.g., via a receiver 220, aresponse to said power request, said response sent from the PSE, saidresponse including a power grant to the access point. Assembly ofcomponents 500 further includes a component 540 configured to determineif the received response indicates a power grant that is less than thedetermined amount that was request and to control operation as afunction of the determination, a component 542 configured to select oneor more access point components or devices coupled to the access pointto de-power, when said response from the PSE indicated a power grantless than the amount of power that was requested, and a component 544configured to operate the access point to de-power the selected one ormore access point components or devices coupled to the access point.

Assembly of components 500 further includes a component 546 configuredto control a monitoring device, e.g., monitoring device 228 or 228′,included in the access point. Component 546 includes a component 548configured to generate and send configuration and control messages tothe monitoring device, a component 550 configured to generate and send aclock signal to the monitoring device, and a component 552 configured toreceive messages communicating current, voltage and/or temperature fromthe monitoring device. Assembly of components 554 further includes acomponent configured to determine received power based on the inputcurrent and input voltage.

FIG. 6 is a drawing of exemplary data/information 600 which may beincluded in an exemplary wireless access point in accordance with anexemplary embodiment. Data/information 600 is, e.g., included in memory224 of wireless access point 202 of FIG. 2 or included in memory 224 ofwireless access point 202′ of FIG. 3.

Data/information 600 includes, in some embodiments, e.g., the embodimentof FIG. 2, a resistance value 602 of the current sense resistor includedin the access point which is used to measure input current.Data/information 600 further includes a generated configurationmessage(s) to a monitoring device including in the access point, e.g.,to a monitoring chip including in the AP. Exemplary information includedin a configuration message includes, e.g., information identifying,specifying or selecting measurements to be performed by the monitoringdevice, e.g., input voltage measurement, input current measurement,voltage drop across a sense resistor coupled to the monitoring device,monitoring device input common mode voltage, temperature, power, etc.,information identifying, specifying or selecting measurement rates,information identifying specifying or selecting information to beincluded in output messages including, e.g. a measured voltage dropacross the sense resistor, a measured input current, a measured inputvoltage, a measured common mode monitoring device input voltage, ameasured temperature, etc., information identifying, specifying orselecting gain factors, e.g. scaling used in the messages, informationidentifying, specifying or selecting message format, and informationidentifying, specifying or selecting output message rate.

Data/information 600 further includes received message(s) 606 from themonitoring device included in the AP, said received messagescommunicating measured voltage(s), measured current, and/or measuredtemperature. In some embodiments, a received message 606 includedmeasured input power, e.g., determined by the monitoring device.

Data/information 600 further includes received measurements for themonitoring device included in the wireless access point 608, e.g.,recovered from received messages 606. Received measurements 608 includesone or more or all of: measured access point input voltage 610, measuredaccess point input current 611, measured access point input power 612,measured access point voltage drop across the sense resistor 613,measured common mode monitoring device input voltage 614, e.g., theaverage of the voltage on monitoring device V+ input and the voltage onmonitoring device V− input, and measured temperature of the AP 616. Insome embodiments, data/information 600 further includes one or more orall of: a determined access point input voltage 618, e.g., determined bythe AP based on a measured common mode monitoring device input voltageand the determined input current, a determined access point inputcurrent 620, e.g., determined by the AP based on the measured voltagedrop across the sense resistor reported by the monitoring device and theknown resistance value of the sense resistor, and a determined accesspoint input power 622, e.g., determined by the access point bymultiplying the measured input current by the measured input voltage.

Data/information 600 further includes a generated message 623 to be sentto the PSE communicating measured voltage, measured current, and/ormeasured power, a determined or estimated traffic load 624, a determinednumber of wireless transmitters to be powered on 626 based on thetraffic load and/or based on device capabilities of UEs connected to theAP, information identifying detected peripheral devices attached to theAP 628, a detected number of peripheral devices attached to the AP 630,information characterizing the detected peripheral devices, e.g.,including power load information, temperature vs power information 634,e.g., to be used in the power request determination with the measuredtemperature, internal access point components vs power information 636,e.g., information specifying amounts of power corresponding to one ormore internal AP components such as wireless radios or wirelesstransmitters included in wireless radios, which may be, and sometimesare, selectively de-powered.

Data/information 600 further includes a determined amount of power to berequested 638, a generated power request message 640 to be sent to thePSE, a received response message from the PSE including a power grant tothe AP 642, a determination as to whether or not the grant is less thanthe requested power level 644, a selected set of access point componentsand/or external devices coupled to the AP, which are to be de-powered ornot received power, in response to the grant being less than therequested power level, and generated control signals to de-powerselected AP components and/or external devices coupled to the accesspoint 648.

FIG. 7 is a drawing of an exemplary assembly of components 700 which maybe, and sometimes is, included in an exemplary power sourcing equipment(PSE), e.g., a network switch, in accordance with an exemplaryembodiment. FIG. 7 is a drawing of an exemplary assembly of components700, which may be, and sometimes is, included in an exemplary PowerSourcing Equipment (PSE), e.g., a network switch, in accordance with anexemplary embodiment. Exemplary assembly of components 700, which may beincluded in a PSE such PSE 101 of FIG. 1 and/or PSE 201 of FIGS. 2 and3, implement steps of an exemplary method, e.g., steps of the method ofthe flowchart 400 of FIG. 4, which are performed by a power servingequipment and/or described with respect to any of the Figures.

Assembly of components 700 can be, and in some embodiments is, used in aPSE 101 of FIG. 1 and/or PSE 201 of FIG. 2 or FIG. 3. The components inthe assembly of components 700 can, and in some embodiments are,implemented fully in hardware within the processor 208, e.g., asindividual circuits. The components in the assembly of components 700can, and in some embodiments are, implemented fully in hardware withinthe assembly of components (AOC) 2018, e.g., as individual circuitscorresponding to the different components. In other embodiments some ofthe components are implemented, e.g., as circuits, within the processor2018 with other components being implemented, e.g., as circuits withinassembly of components 2018, external to and coupled to the processor208. As should be appreciated the level of integration of components onthe processor and/or with some components being external to theprocessor may be one of design choice. Alternatively, rather than beingimplemented as circuits, all or some of the components may beimplemented in software and stored in the memory 209 of the powersourcing equipment, with the components controlling operation of the PSEto implement the functions corresponding to the components when thecomponents are executed by a processor, e.g., processor 208. In somesuch embodiments, the assembly of components 700 is included in thememory 209. In still other embodiments, various components in assemblyof components 700 are implemented as a combination of hardware andsoftware, e.g., with another circuit external to the processor 208providing input to the processor 208 which then under software controloperates to perform a portion of a component's function. While processor208 is shown in the FIGS. 2 and 3 embodiments as a single processor,e.g., computer, it should be appreciated that the processor 208 may beimplemented as one or more processors, e.g., computers.

When implemented in software the components include code, which whenexecuted by the processor 208, configure the processor 208 to implementthe function corresponding to the component. In embodiments where theassembly of components 700 is stored in the memory 209, the memory 209is a computer program product comprising a computer readable mediumcomprising code, e.g., individual code for each component, for causingat least one computer, e.g., processor 208, to implement the functionsto which the components correspond.

Completely hardware based or completely software based components may beused. However, it should be appreciated that any combination of softwareand hardware, e.g., circuit implemented components may be used toimplement the functions. As should be appreciated, the componentsillustrated in FIG. 7 control and/or configure power sourcing equipment,e.g., PSE 101 or PSE 201 or elements therein such as the processor 208,to perform the functions of corresponding steps illustrated and/ordescribed in the method of one or more of the flowcharts, signalingdiagrams and/or described with respect to any of the Figures. Thus theassembly of components 700 includes various components that performfunctions of corresponding one or more described and/or illustratedsteps of an exemplary method, e.g., steps of the method of flowchart 400of FIG. 4 and/or described or shown with respect to any of the otherfigures.

Assembly of comments 700 further includes a component 702 configured tooperate the PSE to receive, e.g., via receiver 207, from the accesspoint, at least one of: i) the measured current and measured voltage itii) a measured power to the PSE, wherein the measured power equals themeasured current multiplied by the measured voltage, a component 703configured to determine an amount of power lost on the PoE cable (e.g.,power loss over power lines (282, 283, 284, 285) of PoE cable 203)coupling the PSE to the access point, e.g., based on received voltage,current, and/or power measurement information from the access point andknown power supply output information at the PSE, and component 704configured to operate the PSE to receive, e.g., via receiver 207, fromthe access point, a power request indicating a determined powerrequirement. Assembly of components 700 further includes a component 706configured to determine at least one of a current, voltage or power toapply to the power lines used to supply power to the access point basedon the request amount of power and at least one of: the communicatedmeasured current and measured voltage or ii) the communicated measuredpower. Assembly of components 700 further includes a component 708configured to generate a response to said received power request fromthe access point, said response communicating a power grant to theaccess point, and a component 710 configured to operate the PSE to send,e.g, via transmitter 205, said generated response to said received powerrequest from the access point, said response communicating a power grantto the access point. Assembly of components 712 further includes acomponent 712 configured to operate the PSE, e.g., control DC powersupply 206, to supply power to the access point in accordance with thepower grant. In some embodiments controlling the DC power supplyincludes adjusting the voltage level across the B+ (213/214) withrespect to B− (215/216).

FIG. 8 is a drawing of exemplary data/information which may be includedin an exemplary power sourcing equipment (PSE), e.g., a network switch,in accordance with an exemplary embodiment. Data/information 800 is,e.g., included in memory 209 of PSE 201 of FIG. 2 or FIG. 3.

Data/information 800 includes a received message from an access pointcommunicating measured voltage, measured current and/or measured power802, e.g., communicating access point measured voltage across its inputpower lines, access point measured input current, and/or access pointmeasured received power. Data/information 800 further includes areceived message from the access point communicating a power requestfrom the access point 804, a determined power loss over the PoE cablecoupled the PSE to the access point 806, and a determined amount ofpower to be granted to the access point 808.

In some embodiments, data/information 800 includes a determined currentto apply to the power lines, e.g., current to sent into one or more B+lines to the AP, to supply power to the access point based on therequested amount of power and at least one of: i) the communicatedmeasured current and voltage or ii) the communicated measured power 810.In some embodiments, data/information 800 includes a determined currentto voltage to the power lines, e.g., voltage to be applied across the B+line(s) with respect to the B− line(s) coupled to the AP, to supplypower to the access point based on the requested amount of power and atleast one of: i) the communicated measured current and voltage or ii)the communicated measured power 812. In some embodiments,data/information 800 includes a determined power to apply to the powerlines, to supply power to the access point based on the requested amountof power and at least one of: i) the communicated measured current andvoltage or ii) the communicated measured power 814.

Data/information 800 further includes a response message to the accesspoint communicating a power grant to the access point 816, and generatedcontrol signal(s) to control the PSE to output power toward the accesspoint in accordance with the grant, e.g., control signals to control thePSE power supply 206 to supply power to the AP in accordance with thegrant.

The PSE, e.g., a PoE switch, receives the PoE power request from one ormore PDs and, in some cases, the measured line voltage, current, and/ortemperature at the requesting device. The PSE takes into considerationthe received measurement information, e.g., voltage at the PD, currentat the PD, and/or temperature. In some embodiments the PSE estimates theamount of power loss to the device due to transmission loss and takesthis into consideration when determining the amount of power to besupplied to the requesting device. For example, the amount of powerexpected to be lost due to transmission may be added to the amount ofpower requested when determining the requesting PDs actual power needs.

Based on the amount of power available at the PSE, the requested amountof power and reported measurement information from one or more PDs, thePSE determines the amount of power to be provided to individual PDsrequesting power. In some cases, depending on the priority of the deviceand/or the number of devices requesting power, the PSE may or may notgrant a PD all the power it is requesting.

The amount of power granted to individual PDs is communicated from thePSE to the PDs to which power grants are made. The power grant may, andin some embodiments does, not take into consideration the amount ofpower the PD allocated to transmission loss. The amount of powerindicated as being granted to a PD that is subject to a largetransmission loss may be lower, e.g., one or several watts lower, thanthe actual amount of power allocated by the PSE. In this way. PDs canmake power requests based on their actual expected needs, potentiallyplus some safety factor, without having to worry if they will sufferfrom extensive transmission power loss due to whether they are connectedto the PSE by a short or long set of lines.

NUMBERED LIST OF EXEMPLARY METHOD EMBODIMENTS Method Embodiment 1

A method, the method comprising: measuring (404), in an access point, aninput current for the access point; measuring (414), in the accesspoint, a voltage on a Power Over Ethernet (PoE) power input of theaccess point; determining (422), in the access point, based on themeasured current, measured voltage, and information about powerrequirements of access point components or devices (e.g., peripheraldevices) coupled to the access point a power requirement of the accesspoint, said power requirement being an amount of power to be requested;and communicating (434), from the access point, a power request to aPower Sourcing Equipment (PSE) indicating the determined powerrequirement.

Method Embodiment 2

The method of Method Embodiment 1, wherein measuring (404), in an accesspoint, an input current for the access point includes: measuring (406),in the access point, a current through a sense resistor, said senseresistor being in series with a Power over Ethernet (PoE) power input ofthe access point.

Method Embodiment 3

The method of Method Embodiment 1, wherein measuring (402), in an accesspoint, an input current for the access point includes: measuring (408),in the access point, a current through an input power feed line coupledto a Power over Ethernet (PoE) power input of the access point, saidcurrent measurement being performed using an inductive sensor.

Method Embodiment 4

The method of Method Embodiment 1, wherein said access point is aPowered Device (PD).

Method Embodiment 5

The method of Method Embodiment 4, wherein said access point is poweredby said PSE.

Method Embodiment 6

The method of Method Embodiment 5, wherein said PSE supports PoE+, andwherein said access point is a PoE+ device.

Method Embodiment 7

The method of Method Embodiment 2, wherein measuring (406) a currentthrough a sense resistor includes: measuring (410) a voltage drop acrosssaid sense resistor; and determining (412) the current based on themeasured voltage drop across the sense resistor and the known value ofthe sense resistor.

Method Embodiment 8

The method of Method Embodiment 1, wherein said devices coupled to saidaccess point include: one or more of: other powered PDs (an additionalPoE APs or a different type of PoE device), USB powered devices, andInternet of Things (IoT) devices.

Method Embodiment 9

The method of Method Embodiment 1, further comprising: measuring (416),in the access point, a temperature at the access point; and whereindetermining (422), a power requirement at the access point includesdetermining (424) the power requirement of the access point based on themeasured temperature in addition to the measured current, measuredvoltage, and the power requirements of access point components ordevices coupled to the access point.

Method Embodiment 10

The method of Method Embodiment 1, further comprising: communicating(432), from the access point, at least one of: i) the measured currentand measured voltage or ii) a measured power to the PSE, wherein saidmeasured power equals the measured voltage multiplied by the measuredcurrent.

Method Embodiment 11

The method of Method Embodiment 10 further comprising: operating (436)the PSE to determine at least one of a current, voltage, or power toapply to power lines used to supply power to the access point based onthe requested amount of power and one of: i) the communicated measuredcurrent and measured voltage or ii) the communicated measured power.(PSE can take into consideration voltage drop/power loss on line todetermine the power to be applied at the PSE, e.g., the access point maynot be aware of the amount of line loss but once i) access pointmeasured voltage and current or ii) access point measured power isreported to the PSE, the PSE can factor into its power calculations thepower loss since the PSE measures voltage at its location on the linesbeing used to supply power to the AP).

Method Embodiment 12

The method of Method Embodiment 1, further comprising: determining(418), at the access point, a number of wireless transmitters to poweron based on a traffic load to be communicated; and wherein said step ofdetermining (422) the amount of power to be requested is further basedon the determined number of wireless transmitters to be powered on(426).

Method Embodiment 13

The method of Method Embodiment 12, further comprising: detecting (420),at the access point, peripheral devices attached to said access point;and wherein said step of determining (422) the amount of power to berequested is further based on the peripheral devices which are detectedas being attached to said access point (428).

Method Embodiment 14

The method of Method Embodiment 9, further comprising: receiving (228),at the access point, a response to said power request from the PSE; andselecting (442), at the access point, one or more access pointcomponents or devices coupled to the access point to de-power when saidresponse to said power request from the PSE indicated a power grant thatis less than the determined amount of power that was requested.

Method Embodiment 15

The method of Method Embodiment 14, further comprising: operating (444)the access point to de-power the selected one or more access pointcomponents or devices coupled to the access point.

Method Embodiment 16

The method of Method Embodiment 9, further comprising: repeating saidsteps of measuring (repeat 402), in said access point, an input current;measuring (repeat 404), in the access point, a voltage on the PoE inputof the access point; determining (repeat 422), in the access point,based on the measured current, measured voltage, and information aboutpower requirements of access point components or devices (e.g.,peripheral devices) coupled to the access point a power requirement ofthe access point, said power requirement being an amount of power to berequested; and communicating (repeat 434), from the access point, apower request to the Power Sourcing Equipment (PSE) indicating thedetermined power requirement.

NUMBERED LIST OF EXEMPLARY APPARATUS EMBODIMENTS Apparatus Embodiment 1

An access point (104 or 202 or 202′) comprising: a plurality of wirelessinterfaces (259, 260, 261, 262); a Power over Ethernet (PoE) power input(238/239); one of a: current sense resistor (235) or an inductivecurrent sensor (235′) for measuring the input current (IIN 298) to theaccess point provided via the POE power input (238/239); a voltagemeasurement device (250 or 250′) for measuring at least one of: i) avoltage (VIN 298) on a Power Over Ethernet (PoE) power input (238/239)of the access point (e.g., with respect a PoE power input low side(240/241) and/or PD input ground (291)) or ii) a voltage drop (e.g.,(value at V+)−(value at V−)) across said sense resistor (235); aprocessor (223) configured to determine, in the access point, based onthe measured current, measured voltage, and information about powerrequirements of access point components or devices (e.g., peripheraldevices) coupled to the access point a power requirement of the accesspoint, said power requirement being an amount of power to be requested;and an interface (219) for communicating (434), from the access point, apower request to a Power Sourcing Equipment (PSE) (201), the powerrequest indicating the determined power requirement.

Apparatus Embodiment 2

The access point (104 or 202 or 202′) of Apparatus Embodiment 1, furthercomprising: a monitoring device (228 or 228′); and wherein saidmonitoring device (228 or 228′) includes said voltage measurement device(250 or 250′).

Apparatus Embodiment 3

The access point (104 or 202 or 202′) of Apparatus Embodiment 2, whereinsaid monitoring device (228 or 228′) is an integrated circuit chip(e.g., chip including a high side current-sense amplifier with anintegrated ADC and a gain block).

Apparatus Embodiment 4

The access point (104 or 202′) of Apparatus Embodiment 2, wherein saidmonitoring device (228′) further includes: a current measurement device(2501) (e.g., current measurement circuitry coupled to said inductivecurrent sensor (235′)).

Apparatus Embodiment 5

The access point (104 or 202 or 202′) of Apparatus Embodiment 1, furthercomprising: a temperature sensor (251), in the access point, formeasuring a temperature at the access point; and wherein the processor(223) is further configured to use the measured temperature whendetermining the power requirement at the access point in addition to themeasured current, measured voltage, and the power requirements of accesspoint components or devices coupled to the access point.

Apparatus Embodiment 6

The access point (104 or 202 or 202′) of Apparatus Embodiment 1, furthercomprising: a transmitter (222) for transmitting signals through saidinterface (219); wherein said interface (219) is a POE interface (e.g.,a PoE+ interface); and wherein the processor (223) is further configuredto control the transmitter (222) to send from the access point, at leastone of: i) the measured current and measured voltage or ii) a measuredpower to the PSE, wherein said measured power equals the measuredvoltage multiplied by the measured current.

Apparatus Embodiment 7

The access point (104 or 202 or 202′) of Apparatus Embodiment 6, whereinthe processor (223) is further configured to: determine a number ofwireless transmitters (2592, 2602, 2612, 2622) to power on based on atraffic load to be communicated; and use the number of wirelesstransmitters to be powered on as part of determining the amount of powerto be requested.

Apparatus Embodiment 8

The access point (104 or 202 or 202′) of Apparatus Embodiment 7, furthercomprising: a receiver (220) for receiving a response from the PSE (201)to said power request; and wherein the processor (223) is furtherconfigured to select, at the access point, one or more access pointcomponents (2592, 2602, 2612, 2622) or devices (269, 270, 271, 272, 273)coupled to the access point to de-power when said response to said powerrequest from the PSE indicated a power grant that is less than thedetermined amount of power that was requested.

Apparatus Embodiment 9

The access point (104 or 202 or 202′) of Apparatus Embodiment 7, whereinthe processor (223) is further configured to: de-power the selected oneor more access point components or devices coupled to the access point.

Numerous variations on the above described methods and apparatus arepossible.

The techniques of various embodiments may be implemented using software,hardware and/or a combination of software and hardware. Variousembodiments are directed to apparatus, e.g., Power Sourcing Equipments(PSEs), e.g., network switches supporting Power over Ethernet, PoEpowered devices, such as wireless access points, base stations, PoEcables, etc, and communications systems. Various embodiments are alsodirected to methods, e.g., method of controlling and/or operating acommunications device or devices, e.g., PD such as a wireless accesspoint, a PSE such as a network switch, and/or communications systems.Various embodiments are also directed to non-transitory machine, e.g.,computer, readable medium, e.g., ROM, RAM, CDs, hard discs, etc., whichinclude machine readable instructions for controlling a machine toimplement one or more steps of a method.

It is understood that the specific order or hierarchy of steps in theprocesses disclosed is an example of exemplary approaches. Based upondesign preferences, it is understood that the specific order orhierarchy of steps in the processes may be rearranged while remainingwithin the scope of the present disclosure. The accompanying methodclaims present elements of the various steps in a sample order, and arenot meant to be limited to the specific order or hierarchy presented.

In various embodiments devices and nodes described herein areimplemented using one or more components to perform the stepscorresponding to one or more methods, for example, input voltagemeasurement at an PoE input of a wireless AP, which is a PD, inputcurrent measurement of the current being received at the wireless AP,which is a PD, power measurement, determination of required power for aPD, determination of the number of wireless transmitters in an AP to bepowered on, determination of the number of external devices coupled toan access point which are to be powered via the access point,determination as to whether or not an AP has received the previouslyrequested amount of power in a response including a power grant,determination of cable power loss by a PSE, determination of an amountof power to be granted to a PD by an PSE, selection of components ordevices to de-power within a PD in response to a power grant being lessthan a request, controlling power at the PSE taking inti account powerloss over the PoE cable and reported measured power at the PD, signalgeneration, transmitting, processing, analyzing, and/or receiving steps.Thus, in some embodiments various features are implemented usingcomponents. Such components may be implemented using software, hardwareor a combination of software and hardware. In some embodiments eachcomponent is implemented as an individual circuit with the device orsystem including a separate circuit for implementing the functioncorresponding to each described component. Many of the above describedmethods or method steps can be implemented using machine executableinstructions, such as software, included in a machine readable mediumsuch as a memory device, e.g., RANI, floppy disk, etc. to control amachine, e.g., general purpose computer with or without additionalhardware, to implement all or portions of the above described methods,e.g., in one or more nodes. Accordingly, among other things, variousembodiments are directed to a machine-readable medium e.g., anon-transitory computer readable medium, including machine executableinstructions for causing a machine, e.g., processor and associatedhardware, to perform one or more of the steps of the above-describedmethod(s). Some embodiments are directed to a device including aprocessor configured to implement one, multiple or all of the steps ofone or more methods of the invention.

In some embodiments, the processor or processors, e.g., CPUs, of one ormore devices, e.g., communications devices such as wireless accesspoints, which are PoE PD devices, or PSE devices, such as networkswitches supporting PoE, are configured to perform the steps of themethods described as being performed by the devices. The configurationof the processor may be achieved by using one or more components, e.g.,software modules, to control processor configuration and/or by includinghardware in the processor, e.g., hardware modules, to perform therecited steps and/or control processor configuration. Accordingly, somebut not all embodiments are directed to a communications device, e.g.,user equipment, with a processor which includes a module correspondingto each of the steps of the various described methods performed by thedevice in which the processor is included. In some but not allembodiments a communications device includes a component correspondingto each of the steps of the various described methods performed by thedevice in which the processor is included. The components may beimplemented purely in hardware, e.g., as circuits, or may be implementedusing software and/or hardware or a combination of software andhardware.

Some embodiments are directed to a computer program product comprising acomputer-readable medium comprising code for causing a computer, ormultiple computers, to implement various functions, steps, acts and/oroperations, e.g. one or more steps described above. Depending on theembodiment, the computer program product can, and sometimes does,include different code for each step to be performed. Thus, the computerprogram product may, and sometimes does, include code for eachindividual step of a method, e.g., a method of operating acommunications device, e.g., a wireless access point which is a PoE PD,a PSE such as a network switch, which supports PoE, a communicationssystem in which PoE is used, etc. The code may be in the form ofmachine, e.g., computer, executable instructions stored on acomputer-readable medium such as a RAM (Random Access Memory), ROM (ReadOnly Memory) or other type of storage device. In addition to beingdirected to a computer program product, some embodiments are directed toa processor configured to implement one or more of the variousfunctions, steps, acts and/or operations of one or more methodsdescribed above. Accordingly, some embodiments are directed to aprocessor, e.g., CPU, configured to implement some or all of the stepsof the methods described herein. The processor may be for use in, e.g.,a communications device or other device described in the presentapplication.

While described in the context of a communications system includingcellular, WiFi, Bluetooth and BLE, at least some of the methods andapparatus of various embodiments are applicable to a wide range ofcommunications systems including many non-OFDM and/or non-cellularsystems.

Numerous additional variations on the methods and apparatus of thevarious embodiments described above will be apparent to those skilled inthe art in view of the above description. Such variations are to beconsidered within the scope. The methods and apparatus may be, and invarious embodiments are, used with CDMA, orthogonal frequency divisionmultiplexing (OFDM), WiFi, Bluetooth, BLE, and/or various other types ofcommunications techniques which may be used to provide wirelesscommunications links between access nodes and wireless nodes. In someembodiments the access nodes are implemented as base stations whichestablish communications links with user equipment devices, e.g., mobilenodes, using WiFi, Bluetooth, BLE, OFDM and/or CDMA. In variousembodiments the wireless nodes are implemented as notebook computers,personal data assistants (PDAs), or other portable devices includingreceiver/transmitter circuits and logic and/or routines, forimplementing the methods.

What is claimed:
 1. A method, comprising: determining, by an accesspoint, an amount of traffic communicated by the access point during apredefined elapsed time period; determining, by the access point, basedon the amount of traffic, a number of wireless transmitters;determining, by the access point, based on the number of wirelesstransmitters, a power requirement of the access point; andcommunicating, by the access point, a power request to a Power SourcingEquipment (PSE), indicating the determined power requirement.
 2. Themethod of claim 1, further comprising measuring, by the access point, aninput current or a voltage on a Power Over Ethernet (PoE) power input ofthe access point, wherein the determining of the power requirement isfurther based on the measured input current or voltage.
 3. The method ofclaim 2, further comprising measuring the input current through a senseresistor, the sense resistor being in series with the Power overEthernet (PoE) power input of the access point.
 4. The method of claim1, further comprising measuring, by the access point, a temperature,wherein the determining of the power requirement of the access point isfurther based on the temperature.
 5. The method of claim 1, furthercomprising: receiving, by the access point, from the PSE, a powerrequest response; determining the response indicates a power grant lessthan the determined power requirement; and de-powering, by the accesspoint, and in response to the determination, an access point componentor a device coupled to the access point.
 6. An access point comprising:a Power over Ethernet (PoE) power input; hardware processing circuitry;and an electronic memory storing instructions that when executedconfigure the hardware processing circuitry to perform operationscomprising: determining an amount of traffic communicated by the accesspoint during a predefined elapsed time period, determining, by theaccess point, based on the amount of traffic, a number of wirelesstransmitters, determining, by the access point, based on the number ofwireless transmitters, a power requirement of the access point, andcommunicating, from the access point, a power request to a PowerSourcing Equipment (PSE), the power request indicating the determinedpower requirement.
 7. The access point of claim 6, further comprisingone of a current sense resistor or an inductive current sensor, theoperations further comprising measuring an input current based on thecurrent sense resistor or inductive current sensor, wherein thedetermining of the power requirement is further based on the inputcurrent.
 8. The access point of claim 7, further comprising a voltagemeasurement component, the operations further comprising measuring,based on the voltage measurement component, a voltage, wherein thedetermining of the power requirement is further based on the voltage. 9.The access point of claim 8, wherein the operations further comprisemeasuring a voltage drop across the sensor resistor, wherein thedetermining of the power requirement is based on the voltage drop. 10.The access point of claim 8, the operations further comprising:measuring a second input current; measuring a second voltage on the PoEinput of the access point; determining based on the measured secondinput current, the second measured voltage, and information about powerrequirements of the access point components or devices coupled to theaccess point, a second power requirement of the access point; andcommunicating a second power request to the Power Sourcing Equipment(PSE) indicating the determined second power requirement.
 11. The accesspoint of claim 8, the operations further comprising communicating atleast one of the measured input current, the measured voltage or ameasured power to the PSE, wherein the measured power equals themeasured voltage multiplied by the measured input current.
 12. Theaccess point of claim 8, further comprising: a POE interface; and atransmitter operably connected to the POE interface, and the operationsfurther comprising controlling the transmitter to transmit at least oneof the measured input current, measured voltage or a measured power tothe PSE, wherein the measured power is the measured voltage multipliedby the measured current.
 13. The access point of claim 6, furthercomprising a temperature sensor, wherein the operations further comprisedetermining, based on the temperature sensor, a temperature, wherein thedetermining of the power requirement is further based on thetemperature.
 14. The access point of claim 6, further comprising areceiver, the operations further comprising: receiving, via thereceiver, a response from the PSE to the power request; determining,that the response indicates a power grant less than the determined powerrequirement; and de-powering, in response to the determining, an accesspoint component or a device coupled to the access point.
 15. Anon-transitory computer readable storage medium comprising instructionsthat when executed configure hardware processing circuitry to performoperations comprising: determining, by an access point, an amount oftraffic communicated by the access point during a predefined elapsedtime period; determining, by the access point, based on the amount oftraffic, a number of wireless transmitters; determining, by the accesspoint, based on the number of wireless transmitters, a power requirementof the access point; and communicating, by the access point, a powerrequest to a Power Sourcing Equipment (PSE), the power requestindicating the determined power requirement.
 16. The non-transitorycomputer readable storage medium of claim 15, the operations furthercomprising measuring, by the access point, an input current or a voltageon a Power Over Ethernet (PoE) power input of the access point, whereinthe determining of the power requirement is further based on themeasured input current or voltage.
 17. The non-transitory computerreadable storage medium of claim 16, the operations further comprisingmeasuring the input current through a sense resistor, the sense resistorbeing in series with the Power over Ethernet (PoE) power input of theaccess point.
 18. The non-transitory computer readable storage medium ofclaim 17, the operations further comprising measuring, via an inductivesensor, the input current through an input power feed line coupled tothe PoE power input of the access point.
 19. The non-transitory computerreadable storage medium of claim 15, the operations further comprisingmeasuring, by the access point, a temperature, wherein the determiningof the power requirement of the access point is further based on thetemperature.
 20. The non-transitory computer readable storage medium ofclaim 15, the operations further comprising: receiving, by the accesspoint, from the PSE, a power request response; determining the responseindicates a power grant less than the determined power requirement; andde-powering, by the access point, and in response to the determination,an access point component or a device coupled to the access point.